Engine Surges between 500 & 1000 RPM?

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Engine Surges between 500 & 1000 RPM?

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Mustang >> Ford Mustang Tech >> 5.0 Mustang >> Engine Surges between 500 & 1000 RPM?

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Engine Surges between 500 & 1000 RPM? - 5/10/2008 7:16:12 PM

medium_jay

Posts: 77
Joined: 4/24/2007
Status: offline

Hey guys. My 1990 5.0 Mustang Lx seems to surge betweem 500 and 1000 RPM at idle. (tacometer bounces up and down) What is the cause of this, and more importantly how can this problem be fixed? If someone could answer this question for me and how to fix it with the best possible explanation that would be really awesome. Thanks for taking the time to read my post! Thanks.

Chef

Post #: 1

RE: Engine Surges between 500 & 1000 RPM? - 5/10/2008 9:22:06 PM

mjr46

Posts: 10877
Joined: 6/13/2007
Status: offline

run a koer test and check for codes ..after that check for vaccum leaks and then after that clean IAC motor and throttle body

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RE: Engine Surges between 500 & 1000 RPM? - 5/11/2008 7:29:36 AM

Texas5.0

Posts: 664
Joined: 12/24/2006
From: South Texas
Status: offline

It took me almost a year to find the problem.... vacuum leaks were mine. The lower intake was not sealed. Took a smoke test to find it. Good luck and hang in there - follow what these guys tell you and you will figure it out.

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ORIGINAL: my77stang
i''''d hit it...... with a board........ to knock her out so i could gain entry to the poopar

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RE: Engine Surges between 500 & 1000 RPM? - 5/11/2008 8:36:22 AM

floodzilla

Posts: 531
Joined: 2/22/2008
From: L.I. New York
Status: offline

def sounds like a vaccumm leak somewhere.

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Masterpower t70 turbo
46 lbs injectors
water/methanol
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RE: Engine Surges between 500 & 1000 RPM? - 5/11/2008 8:53:16 AM

sethta

Posts: 39
Joined: 11/21/2007
Status: offline

Check your tps too. It should read between about .96-.99 volts at idle.

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RE: Engine Surges between 500 & 1000 RPM? - 5/11/2008 10:00:40 AM

Joel5.0

Posts: 2787
Joined: 1/9/2006
From: Puerto Rico
Status: offline

Suggestions:

DIY KOEO/KOER/Cylinder Balance Self-Test

Base Idle Reset Procedure

quote:

ORIGINAL: sethta

Check your tps too. It should read between about .96-.99 volts at idle.

Nope.... as long as the TPS is between .7 - 1.0 vdc, it'll work fine.

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Post #: 6